It has been shown that tumors have developed numerous ways to escape tumor specific immune responses. These mechanisms will ultimately not only enhance tumor growth, but also impair the effect of immune based therapies in cancer. In the past year we were able to comlet a study showing how mice with fatty liver disease evade T cell immunity. We showed that linoleic acid, which accumulates in mice with fatty liver disease specifically kills CD4 T cells leading to tumor growth. Resuce of CD4 cells using anti-oxidants was able to dely tumor growth.